FCC To Investigate Raised RF Noise Floor

If you stand outside on a clear night, can you see the Milky Way? If you live too close to a conurbation the chances are all you’ll see are a few of the brighter stars, the full picture is only seen by those who live in isolated places. The problem is light pollution, scattered light from street lighting and other sources hiding the stars.

The view of the Milky Way is a good analogy for the state of the radio spectrum. If you turn on a radio receiver and tune to a spot between stations, you’ll find a huge amount more noise in areas of human habitation than you will if you do the same thing in the middle of the countryside. The RF noise emitted by a significant amount of cheaper modern electronics is blanketing the airwaves and is in danger of rendering some frequencies unusable.

Can these logos really be trusted? By Moppet65535 (Own work) [CC BY-SA 3.0], via Wikimedia Commons
Can these logos really be trusted? By Moppet65535 (Own work) [CC BY-SA 3.0], via Wikimedia Commons
If you have ever designed a piece of electronics to comply with regulations for sale you might now point out that the requirements for RF interference imposed by codes from the FCC, CE mark etc. are very stringent, and therefore this should not be a significant problem. The unfortunate truth is though that a huge amount of equipment is finding its way into the hands of consumers which may bear an FCC logo or a CE mark but which has plainly had its bill-of-materials cost cut to the point at which its compliance with those rules is only notional. Next to the computer on which this is being written for example is a digital TV box from a well-known online retailer which has all the appropriate marks, but blankets tens of megahertz of spectrum with RF when it is in operation. It’s not faulty but badly designed, and if you pause to imagine hundreds or thousands of such devices across your city you may begin to see the scale of the problem.

This situation has prompted the FCC Technological Advisory Council to investigate any changes to the radio noise floor to determine the scale of the problem. To this end they have posted a public notice (PDF) in which they have invited interested parties to respond with any evidence they may have.

We hope that quantifying the scale of the RF noise problem will result in some action to reduce its ill-effects. It is also to be hoped though that the response will not be an ever-tighter set of regulations but greater enforcement of those that already exist. It has become too easy to make, import, or sell equipment made with scant regard to RF emissions, and simply making the requirements tougher for those designers who make the effort to comply will not change anything.

This is the first time we’ve raised the problem of the ever-rising radio noise floor here at Hackaday. We have covered a possible solution though, if stray RF is really getting to you perhaps you’d like to move to the National Radio Quiet Zone.

[via Southgate amateur radio news]

Brutal Water Cannon Defeats Summer Heat; Kills It On Documentation

There’s a war on, and while this over-the-top water blaster is certainly an escalation in the Water Wars arms race, that’s not the war we’re referring to. We’re talking about the Documentation War. Hackers, you’re on notice.

Gj3YAOLIf you want to see how a project should be documented, look no further than [Tim]’s forum posts over at WaterWar.net. From the insanely detailed BOM with catalog numbers and links to supplier websites, to scads of build photos with part number callouts, to the finely detailed build instructions, [Tim] has raised the stakes for anyone that documents any kind of build.

And that’s not even touching on the merits of the blaster itself, which has air and water tanks plumbed with every conceivable valve and fitting. There’s even an inline stream straightener made of bundled soda straws to keep the flow as laminar as possible. It looks like [Tim] and his colleagues are obsessed with launching streams of water as far as possible, and although bad weather has prevented an official measurement so far, from the video below it sure looks like he’s covering a huge distance with a stream that stays mostly intact to deliver the full blast to its intended target without losing a drop.

For as much fun as amped-up water guns appear to be, we haven’t seen too many grace these pages before. Going way back we covered a DIY super-soaker. For something much less involved than [Tim’s] masterpiece, you can pull together this pressurized water pistol in an afternoon.

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